Electrophotographic copying apparatus of slit exposure type

ABSTRACT

An electrophotographic copying apparatus of slit exposure type comprises a sheet original conveyor mechanism provided on top of the machine housing, and an original carriage having a transparent sheet of glass or the like provided contiguously with the frame of the conveyor mechanism. When a sheet original is to be copied, such original is transported by the sheet original conveyor mechanism for a through-slit exposure. When a thick original such as book or the like is to be copied, the original carriage with the thick original thereon is forced to move with the conveyor mechanism to disconnect the mechanism from its drive system but connect the drive system to the original carriage, whereafter the carriage is moved for the thick original thereon to be subjected to a through-slit exposure.

Unite States Patent 1 Komori et al.

1 ELECTROPHOTOGRAPHIC COPYING APPARATUS OF SLlT EXPOSURE TYPE [75] Inventors: Shigehiro Komori, Yokohama;

Jiro Sato, Kawasaki; Hiroyoki Hattori, Tokyo, all of J apan [73] Assignee: Canon Kabushiki Kaisha, Tokyo,

Japan [22] Filed: Dec. 23, 1971 [21] Appl. No.: 211,383

[30] Foreign Application Priority Data Dec. 30, 1970 Japan 45/126316 [52] US. Cl. 355/8, 355/81, 355/84,

' 271/54 [51] Int. Cl. G03g 15/04 [58] Field of Search ..355/8,1l, 3, 81,

[56] References Cited UNITED STATES PATENTS 3,510,218 5/1970 Limberger et al. 355/8 June 19, 1973 3,597,074 8/1971 Murgas et al. 355 75 Primary Examiner-Robert P. Greiner Att0meyJoseph M. Fitzpatrick, John Thomas Cella, Charles B. Cannon et al.

[5 7] ABSTRACT An electrophotographic copying apparatus of slit exposure type comprises a sheet original conveyor mechanism provided on top of the machine housing, and an original carriage having a transparent sheet of glass or the like provided contiguously with the frame of the conveyor mechanism. When a sheet original is to be copied, such original is transported by the sheet original conveyor mechanism for a through-slit exposure. When a thick original such as book or the like is to be copied, the original carriage with the thick, original thereon is forced to move with the conveyor mechanism to disconnect the mechanism from its drive system but connect the drive system to the original carriage, whereafter the carriage is moved for the thick original thereon to be subjected to a through-slit exposure.

5 Claims, 25 Drawing Figures Patented June 19, 1973 17 Sheets-$heet l Patented June 19, 1973 1'? Sheets-Sheet 2 Patented June 19, 1973 17 Shee ts-Shee t 4 Patented June 19, 1973 3,740,133

17 Sheets-Sheet 5 FIG. 5

ml I w' MS I Patented June 19, 1973 17 Sheets-Sheet 6 Patentad Juhe 19, 1973 17 Sheets-Sheet 7 3m 3m 3m 82 02 M m 2 M -22 oz 32 \M a2 0 2 1 AXQ O m Patented June 19, 1913 17 Sheets-Sheet 8 Patented June 19, 1973 3,740,133

17 Sheets4heet 9 FIGIO Patented June 19, 1973 3,740,133

17 Sheets-Sheet 1O Patehted June 19, 1973 17 Sheets-Sheet 11 Patented June 19, 1973 1'7 Sheets-Sheet 12 Patented June 19, 1973 17 Sheets-Sheet 1 3 Patented June 19, 1973 17 Sheets-$heet 14 FIG. I8

Patented June 19, 1973 1'? Sheets-$heet l5 FIG. 20

Patented June 19, 1973 17 Sheets-Sheet l6 Patented June 19, 1973 l7 Sheets-Sheet 16 Patcntgd June 19, 1973 1'7 Sheets-Sheet 1') FIG. 25

ELECTROPHOTOGRAPHIC COPYING APPARATUS OF SLIT EXPOSURE TYPE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a photographic, especially an electrophotographic, copying machine of the through-slit exposure type, and more particularly to a simplified photographic copying machine of such type for use with originals in the form of sheet (hereinafter referred to as sheet originals) and and originals in the form of book or the like (hereinafter referred to as thick originals).

2. Description of the Prior Art While a copying machine exclusively for use with sheet originals cannot copy thick originals such as books or the like, it can copy sheet originals simply by placing such originals in a feed port and does not involve the backward or return stroke of its original supporting carriage or its optical system. Therefore, such copying machine can increase the copying speed and is simple to construct and inexpensive to manufacture.

On the other hand, a copying machine for use with books or other thick originals is characterized by its capability of copying sheet originals as well as thick originals, but the machine of this type involves the procedures of opening an original setting cover, placing a sheet original or a thick original on an original supporting glass sheet, closing the cover and depressing a copy button. Further, the return stroke of its original carriage or its optical system is involved not only to limit the copying speed but also to complicate the machine construction and accordingly increase the cost of the machine.

For these reasons, the copying machines of the foregoing two types have been enjoying their own unique demand.

In offices, however, it is usually the case that sheet originals are copied much more often than books or other thick originals, which are rarely required for copying. In view of such situation, a copying machine of a further type has been proposed which can copy both sheet originals and thick originals without reducing its merits as the sheet original copying machine including the simplicity of construction, a higher copying speed, low cost of the manufacture, etc. This versatile copying machine is either such that the machine parts overlying the passage surface for sheet originals are made into a detachable construction which, for a thick original to be copied, may be detached to expose the sheet original transport rollers of the machine proper, whereby the thick original such as book or the like is manually pressed against these rollers and exposed to light while being moved by the rubber rollers to produce a copy, or such that a carrier formed of transparent glass or plastics sheet is provided to support a book or the like thereon and two or more pairs of transport rollers are provided to hold therebetween the ends of the carrier so as to move the carrier for accomplishing exposure. Such machine is characterized by its relatively low cost of the manufacture, but suffers from various demerits and practical problems as enumerated hereunder.

l. The procedure of detaching some of the machine parts is unavoidably involved.

2. Possible variations in the manual pressure imparted to the book or the like for keeping it against the driven rubber rollers and corresponding variations occurringin the speed at which the book or the like is manually moved along the rubber rollers may cause great variations in load to the drive of the machine proper, which in turn would result in unstability of the formed image and accordingly a seriously reduced quality of the resultant copy.

3. The detection of the leading edge of the original effected by a detection switch is subject to errors which would cause a great degree of irregularity in the location of the leading edge of the resultant copy image, because when opened for copying, the leading edge of the thick original such as book or the like (as viewed in the direction of the original feeding) provides a complicated configuration (due to the presence of its cover or to the inclined edge surface of the book formed when it is opened).

4. The roller driving gear or sprocket wheel located at one end of the original transport rollers is unavoidably projected upwardly beyond the plane of the original passage surface to prohibit flat formation of the original passage surface and accordingly prevent a part of a bulky original from being duly copied.

Also, in the type of machine which is provided with a carrier, cumbersome procedures are involved in the maintenance of the carrier, in addition to the troublesome procedures of mounting and dismounting the same carrier.

SUMMARY OF THE INVENTION In view of the various disadvantages and demerits of prior arts as noted above, the present invention has, for its object, to provide a practical copying machine which holds characteristics as a sheet original copying machine and which can also function as a machine for copying books or other thick originals.

Accordingly to the present invention, a sheet original conveyor mechanism is provided on the top of a machine housing and an original carriage having a transparent sheet of glass or like material is provided contiguously with the frame of said mechanism. Where a sheet original is to be copied, such original is transported by transport rollers included in the sheet original conveyor mechanism and then subjected to a through-slit exposure at an illuminating station. Where a thick original such as book or the like is to be copied, such original is placed on the transparent sheet of the original carriage and forced to move with the conveyor mechanism to thereby operatively disconnect this mechanism form its drive system and connect this system to a rack or the like forming a part of the original carriage, whereafterthe carriage is moved to pass the thick original thereon through the illuminating station for effecting a through-slit exposure.

Accordingly, the present invention is applicable not only to electrophotographic or electrofax copying machines of the image transfer type but generally to other copying machines of the through-slit exposure type.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the present invention will become fully apparent from the following detailed description of various embodiments thereof taken in conjunction with the accompanying drawings, in which: 

1. A photographic copying machine of the through-slit exposure type comprising: a housing; a through-slit exposure device mounted in said housing; sheet original conveyor means having a sheet passage for transporting a sheet original through said passage and past said through-slit exposure device to form the image of said sheet original on a photosensitive medium; an original carriage mounted for reciprocal movement on said housing and having a transparent plate fixed thereto for supporting a thick original for a movement past said throughslit exposure device to form the image of said thick original on the photosensitive medium; means integrally mounting said conveyor means on said carriage wherein said conveyor means is fixed against movement with respect to said carriage; photographic copy processing means for operation to produce copies of said sheet original and thick original images on said photosensitive medium when one of said originals is moved past said exposure device; and drive system means releasably coupled to said conveyor means for operation to activate said conveyor means to transport said sheet original past said through-slit exposure device while maintaining said carriage in a predetermined stationary position when a sheet original is being copied, and means for decoupling said drive system means from said conveyor means when said carriage is reciprocated to move said thick original past said through-slit exposure device.
 2. A photographic copying machine according to claim 1, wherein said original carriage has driven means, and further comprising means for coupling said driven means to said drive system means for moving said original carriage when said thick original is being copied.
 3. A photographic copying machine according to claim 1, further comprising control means for synchronizing the movement of said sheet and thick originals past said through-slit exposure device with the movement of said photosensitive medium, said control means including a first actuator member operated by said sheet original and a second actuator member operated by a cam formed in said original carriage.
 4. Photocopying apparatus according to claim 1, wherein said transparent is disposed to provide a guide member for said sheet original.
 5. Photocopying apparatus according to claim 5, further comprising locking means for maintaining said carriage in said predetermined stationary position wherein said locking means comprises a projecting member provided on said carriage and resilient holding means mounted on said housing for releasably grasping said projecting member. 